US scientists are warning that radiation from controversial full-body airport scanners has been dangerously underestimated and could lead to an increased risk of skin cancer – particularly in children.

University of California biochemist David Agard said that unlike other scanners, the radiation from these devices is delivered at low energy beam levels, with most of the dose concentrated in the skin and underlying tissue.

“While the dose would be safe if it were distributed throughout the volume of the entire body, the dose to the skin may be dangerously high,” Dr Agard said.

“Ionizing radiation such as the X-rays used in these scanners have the potential to induce chromosome damage, and that can lead to cancer.”

Of further concern is that a failure in the device – like a power or software glitch – could cause an intense radiation dose to a single spot on the skin.